Some scouts who had followed Castillo with the Cuban national team felt he would be a steady, everyday center fielder in the big leagues, while others felt he would fit best as a fourth outfielder, with good speed and defense in center field, a line-drive stroke, an aggressive hitting approach and occasional power.

When Castillo showed up on Saturday at the University of Miami, scouts saw a different physique, which has translated to more power. At 5-foot-9, 205 pounds, Castillo is 20 pounds heavier than he was in Cuba, and it’s in a good way, with plenty of muscle packed on to his athletic frame.

The biggest difference was in Castillo’s power. Scouts get to watch Cuban players take batting practice at international tournaments, and Castillo showed more juice in his bat than he had before he left Cuba. Castillo always had good bat speed and could sting the ball with a line-drive approach in Cuba, but on Saturday he hit balls out to all fields, displaying plus raw power in BP. Several scouts felt Castillo took a home run derby mentality with him into his BP session instead of his standard game swing, but it worked to show some scouts they needed to adjust their grades on him.

“In BP he had some length in his swing, so there was pretty good loft power,” one scout said. “Then in games he shortened up his stroke and we saw the line-drive swing that we saw in the past. But he is a lot more physical than what we saw in his Cuban national days. They really did a hell of a job with the body.”

Several scouts have questions about Castillo’s hitting mechanics, which isn’t uncommon for Cuban players. He has plenty of bat speed, but the swing does get long and there were times when he collapsed on his back side on Saturday. Players are often a product of their environment. Cuban hitters frequently have long swings because they don’t have to be quick and direct to the ball in Serie Nacional, where it’s rare to see anyone throwing 95 mph and most pitchers can’t even crack 90 mph. There’s more margin for error to gear up with some extra length in your swing when the pitcher is throwing 86 instead of 96. Castillo’s short arms help him though, and if he can make the proper adjustments, he has a chance to be a solid hitter, even if he’s not a premium threat at the plate.

When Cuba brings a team to international tournaments, its goal is to win, not showcase players for major league scouts, so scouts don’t get to see players run the 60-yard dash while they’re in Cuba. Instead they rely on their eyes and home-to-first times, and while those can be erratic, Castillo did get down the line in 4.1 seconds from the right side in Cuba, which translates to 70 speed. Even with another 20 pounds to carry, Castillo showed he still has premium wheels, running the 60-yard dash in 6.4 to 6.5 seconds on Saturday, depending on the stopwatch.

Having balls hit to him in the outfield is pretty worthless, since scouts need game situations to get a true read on his jumps, instincts and feel for the position. But scouts who have followed Castillo since he was in Cuba say they’re confident he can play a quality center field, with good reactions and the speed to cover plenty of ground.

Castillo also took groundballs at shortstop, a position he won’t play in the major leagues. It was worth putting him out there, however, in case a team wants to stick its neck on the line and try him at second base (scouts can get a better read on arm strength at shortstop than second). Second base is a position with high demand and low supply, both on the trade block and this offseason’s free agent market. It’s been a long time since Castillo played the infield, with 29 games at second base and seven at third base in 2009-10 before he moved to the outfield, where he won a gold glove in 2011-12. While Alexei Ramirez made the transition from center fielder for his Cuban team to immediate big league shortstop with the White Sox, scouts got to see Ramirez take more groundballs at shortstop and were immediately drawn to his actions there. Castillo, scouts said, looked uncomfortable in the infield and showed less arm strength than he had in the past.

“From watching him take groundballs and throw from shortstop, you can see why he was moved to the outfield,” said another scout. “I understand what agents do to try to create more value, but you have to use a little bit of common sense here. He didn’t even turn double plays at second base. If you really want him in the infield, you need to put him at second base and see him turn double plays. That’s going to be the make or break, and we didn’t see that, and there’s probably a reason why. He’s just not a natural infielder.”

Before Castillo’s rapid strength increase, he was a similar player to Rajai Davis, a 5-foot-9, 195-pound righthanded-hitting outfielder, when they were the same age. Davis, now 33, was another similarly-built speedster who could play center field with an aggressive hitting approach, a solid bat and occasional power, with an underappreciated skill set for a player who was often thought of as a fourth outfielder himself.

Davis might not be the flashiest comp, but during his age 27-29 seasons, Davis amassed 6.5 Wins Above Replacement (per Baseball-Reference.com), with a peak of 3.3 WAR for Oakland as a 28-year-old in 2008. That’s an average of a little over 2 WAR per season at the same age as Castillo, which is a league-average player.

That, however, was before Castillo increased his raw power. If Castillo can give teams comparable production to Davis at the same age with a little extra pop, he might not be a star like Yoenis Cespedes or Jose Abreu, but that’s a very solid everyday player, with no draft picks or prospects to surrender to acquire him.